SAIB CE-05-46

SPECIAL AIRWORTHINESS

INFORMATION BULLETIN

Aircraft Certification Service Washington, DC

U.S. Department of Transportation Federal Aviation Administration

CE-05-46 April 1, 2005 http://www.faa.gov/aircraft/safety/alerts/ This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin (SAIB) advises you, owners and operators of Sierra Hotel Aero, Inc. models Navion and Navion A airplanes equipped with a Continental IO-470-C engine with a rated horsepower of 250 hp at 2,600 r.p.m., of a potential safety problem.

Background

We are aware of several field modifications (approved via the FAA Form 337) of the Navion A aircraft where the Continental IO-470-C engine was installed. This engine has a horsepower increase over the previous engine, yet these aircraft have no known FAA-approved structural modifications to accompany this engine installation. The Navion and Navion A models appear to not have any of the factory-installed structural modifications designed to allow the installation of this engine (as approved for the Navion E as depicted in Aircraft Specification A-782).

Recommendations

We highly recommend that you not install any engine of increased horsepower on any of the Navion series airplanes unless:

• The airplanes are modified following items 139, 140, 141, 142, or Note 6 of Aircraft Specification number A-782; or

• The airplanes are modified following an amendment to Type Certificate number A- 782 as issued through the FAA; or

• The airplane is modified following a Supplemental Type Certificate issued through the FAA.

We are still analyzing this safety issue. We may follow this SAIB with additional actions, which could include issuance of an Airworthiness Directive.

For Further Information, Contact

Mr. Steven J. Rosenfeld, Aerospace Engineer, FAA, Central Region, Chicago Aircraft Certification Office, 2300 East Devon Avenue, Des Plaines, IL 60018; phone: (847) 294-7030;

fax: (847) 294-7834; email:

steven.rosenfeld@faa.gov